silver foil on Cpu copper heatsink?

hi all i upgraded my cpu from a tl56 to tl60 and thus had to remove heatsink to do it.

question is i have upgraded desktop cpus dozens of times with no problems, until this moment when i removed the copper heatsink and found a layer of something i could only say looks like a sheet of aluminium or tin foil on the base of the copper that sits on the cpu, but i could also see faintly a little paste simular to artic silver.

anyway i replaced the heatsink untouched onto new cpu and temp stays between 60-75c. and yes i know i should have applied new thermal compound which i was gonna do but the foil stumped me and i wanted second opinion?

should i remove the silver paper if removable and clean with artic cleaning solutions 1+2 and re-apply artic silver5 or leave it.

also in case asked laptop is on a akasa 17" cooler.

any suggestions as to what the foil is?

thanks

 

My vote is to clean it off with isopropyl alcohol (isopropanol) and reapply AS5. Remember to not over do it w/ the AS

I bet the foil is some kind of heat spreader or it protects the chip from the copper, although I can't imagine why hot silicon needs protecting from copper....

 

cheers for the reply.

im gonna also write a thread in one of the main section as to what the foil is but as you stated and what i was gonna do until the foil stumped me is reapply as5 after cleaning the copper.

thanks for replying